Ultrasonic Vibration Assisted Electrical Discharge Machining and Micro-Electrical Discharge Machining: A Review

Abstract

Material is removed during electrical discharge machining (EDM) because of the high temperatures. Hence, tiny components of the tool and workpiece melt and evaporate, causing molten metal to solidify and form debris. This debris affects process efficiency if not flushed out. To ensure continuous flushing, tools, workpiece or dielectric motion are necessary. Introducing ultrasonic vibrational motion to the tool, workpiece or the dielectric liquid became a viable alternative for the evacuation of debris during the ultrasonic assisted electrical discharge machining (USEDM) and ultrasonic assisted micro-electrical discharge machining (USµEDM) processes. In addition to the US vibration, powder mixed to the dielectric medium, using gas as a dielectric medium, and adopting the magnetic field (MF) assistance in USEDM are additional attempts to improve the performance of these processes. This article reviews the main research directions, process parameters and performance indicators of USEDM and USµEDM processes. Extra enhancement to their performance using powder mixing, gas or MF assistance was also presented. Numerous modeling and optimization methods have also been examined. The study demonstrated the benefits of using US vibration assistance to EDM and micro-electrical discharge machining regarding a faster material removal rate, improved surface quality and decreased electrode wear rate. Finally, the current article identifies potential directions for future studies.